Diesel Injector Guru: Anyone use this service?

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Screwdriver

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Oct 20, 2008
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Welcome to Dieselfuelinjector.guru

I'm tempted to send him my OM616 injectors and lift pump, as I have struggled to find someone who is very familiar and can rebuild these locally. Only challenge is that he is located Stateside.

Anyone use him or someone as focussed solely on our classic parts locally?

Cheers!
 
I wouldn't send them to the USA to get them rebuilt.
$99 for 5 injectors is also too cheap, IMO. For a strip down, clean up, new nozzles, re-shim to balance, then pop test.

I've used these folk to order Bosch parts:
CAE Diesel ltd, Sewardstone Hall Farm, Sewardstone Rd, London, E4 7RH Tel 020 8049 0601

Diesel fuel injection system experts in East London
 
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$99 for 5 injectors is also too cheap, IMO. For a strip down, clean up, new nozzles, re-shim to balance, then pop test.

First time I've heard someone worry about being too inexpensive ;)

The "guru" doesn't include replacement nozzles at that price but he does appear to have a decent following on the US forums. I'm only looking to restore my injectors and lift pump, not order new ones.
 
Hi,
It seems he gives them a good wash and brush up (without a wire brush!)
You are effectively paying for his labour and knowledge - so prices seem fair.
Cheers
Steve
 
First time I've heard someone worry about being too inexpensive ;)

The "guru" doesn't include replacement nozzles at that price but he does appear to have a decent following on the US forums. I'm only looking to restore my injectors and lift pump, not order new ones.

OK. These 'ancient tech' indirect injection units have Bosch DNOSD pintles with a single nozzle.
They are self-cleaning, and as such, don't block. They just wear to the point that the spray pattern goes bad. They will be 'worn' from 100K miles but may still atomise fine. Cleaning them, at any mileage, is therefore not worth doing. Better to test their spray pattern ... if you have reason to. Such as a drop off in performance ( this is the 616! :))

Lift pumps on these also very rarely fail. All they have to do is supply 15 PSI to the HP pump. So if not broken, don't worry.

If an OM616 / 617 is running sub-optimally (assuming the fuel filters are OK), then there are 2 main things to check before suspecting the injectors:
The timing (point of injection - due to cam chain wear) and, much more likely...a lack of any manual valve adjustment over the years - because it's a right pain and thus gets ignored.
 
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Timing and valve adjustment are both recently checked/ adjusted. Diesel purge also done. I intend to supply new nozzles along with my injectors and he will clean, install, test and ship back to me like new for $89. The lift pump is original and I suspect the O-rings are long gone (The IP had what appeared to be old diesel fuel inside it with very little to no oil). It's also covered in rust.

The car experiences two major symptoms only - 1) Really difficult to start cold without a light dab on the throttle. Smokes only on startup. 2) Intermittent stalling when shifting from 2nd/3rd to neutral when coasting to stop. No oil leaks or consumption at all. Excellent power, fuel economy and strong compression.

I've been trying to eliminiate fuel/ air leak issues one by one to address the above symptoms. After this, only thing left would be the injection pump components.
 
Let us know how this goes.

Will do. Here are the nozzles I'm considering supplying for fitment. I've struggled to find the definite "best" nozzle for our injectors. Some say Bozio, other say Monark. And now Firad makes them for our cars as well. Only thing I've heard is that Bosch doesn't make nozzles in the EU anymore, so best avoided.
 
I think that's correct, as I've kept a NOS set to use, eventually.

A friend used Indian Bosch nozzle and said they were fine. He's got a pop tester and shims; the right kit.
 
Just pulled the injectors. The attached pictured show the worst nozzle with tiny craters within the burn area that isn't protected by the heat shields. Looks like it's time for a change.

Wonder what causes the metal to crater like that?
 

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Injectors and lift pump have returned. Total cost of shipping and customs to and from the US was £75/-

A few points to consider:

1) One of my injectors was "weeping". The guru threw in a matched properly functioning injector to complete my set at no added cost.
2) All 4 injectors were surgically cleaned and set at 1725 PSI with the supplied Monark nozzles installed. Balanced at 25 +/- PSI.
3) 4 new, correct heat shields were supplied at no extra cost
4) New injector return hose was supplied at no extra cost
5) As I also purchased an lift pump rebuild, a new overflow valve spring was supplied at no extra cost. I estimate this spring to be 40-50% firmer than my 40+ year old tired factory spring.
6) Lift pump was rebuilt with all new o-rings and correct new gasket was supplied.
7) Total cost all inclusive was £225/-. See pics below.

All in all, I'm very pleased with the service provided. It feels nice to know you're supporting a business run by an fuel system fanatic who specializes in this one area. I plan on repeating this service when my W123 injectors need a look at next year. Now, to get them installed and the car running. I'll post once more to share on the performance improvement.
 

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Circling back to close the loop on this. The Guru's rebuilt injectors have made the car noticeably quieter at idle and much smoother during revving. I wouldn't call the increase in power dramatic but it is definitely an improvement. Overall, incredible value for money for a service that will keep the old girl running for a decade or two more.

Slightly more concerning was learning that the lift pump rebuild kits are no longer available from Bosch. So if you have an old diesel, nows the time to stock up on one for whenever you decide to rebuild it (relatively easy job)
 
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Time for round 2 - this time my W123 injectors are heading over for a rebuild. (Note the 5th injector stuck to the pre-
chamber screw in assembly)

66F739A9-4E03-44DC-85B9-D0C87AD822F2.jpeg
 
Injectors (and lift pump) were returned rebuilt, surgically cleaned with Monark 261 nozzles installed. I learnt that my injectors were set 150 psi lower than recommended specification, which is likely what led to the smoke on startup. Looking forward to experiencing how the ol' girl goes!512bfbd8-1fc8-4cde-9de8-724ce3f6f5e0.jpg
 
Injectors (and lift pump) were returned rebuilt, surgically cleaned with Monark 261 nozzles installed. I learnt that my injectors were set 150 psi lower than recommended specification, which is likely what led to the smoke on startup. Looking forward to experiencing how the ol' girl goes!View attachment 107848
Hi, could you recommend a garage or a specialist for injector rebuild? PeterPodi
 
I've sent two sets of injectors here. Wouldn't trust anyone else with them now that I've experienced the difference. Postage is around £25 each way via UPS.

 
Hi, could you recommend a garage or a specialist for injector rebuild? PeterPodi

Once your injectors arrive rebuilt, take them into Paul at Holford Motors. The owners are helpful, honest ex- Mercedes techs who trained on the 1970s/80s cars and know them really well. £45 an hour 👍

They did my W115 and W123 sets
 

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